The goal of this Fast-Track Phase I/II SBIR is to test a novel extracorporeal system for delivering mesenchymal stem cell (MSC) secretions to treat acute myocardial infarction (MI). We will use the Sentien proprietary extracorporeal delivery system to treat swine subjected to a clinically relevant model of MI. The project specific aims are: (1) Simulated blood perfusion to select most potent MSC bioreactor membrane (Ph. I); (2) Stability analysis of manufactured Sentinel devices (Ph II); and (3) Therapeutic studies of MSC bioreactors in pigs with MI (Ph. II). Our Phase I milestone is the identification of dialyzer membrane to optimize MSC potency. The Phase II deliverables of the studies include (1) protocol for shipping and storage of our devices; (2) assessment of toxicity of our devices in healthy swine; (3) the ideal timing window for efficacious treatment of acute MI in swine; and (4) efficacy data compared to MSC transplantation. With the completion of the studies described herein, our bioreactor will be poised for immediate testing in human patients.